Framework for Estimating Industry-Specific Truck Traffic Volume for Pavement Damage Quantification

A range of studies have evaluated pavement damage attributed to various truck configurations for allocating pavement damage cost to roadway users. There is however, an emerging initiative where agencies are beginning to tie truck traffic to the specific commodities they carry for the purpose of providing a better understanding of the causal relationship between highway maintenance costs and industry haulage practices, and determining reasonable user fees among different industries. Automatic traffic data collectors are commonly used in conjunction with road tubes to classify trucks but they do not capture information about the type of commodity carried. This paper presents a framework for estimating truck volumes associated with a specific industry. The framework is illustrated by estimating truck volumes associated with the logging industry for two highway segments in Northern Wisconsin during one winter and spring cycle. Application of the framework revealed the following: (1) The framework can be extended to estimate truck volumes associated with other industries; (2) Federal Highway Administration (FHWA) vehicle classes 9 and 10 were the main carriers of logs for the segments studied; (3) In general, more logs were carried during winter (December-February) than in the spring (March-May). In the northbound direction of one segment, the peak load occurred in February at 61 trucks/day and dropped to 4 trucks/day in March. The number of loaded logging trucks in February in the northbound direction was approximately eight times that in the southbound direction; and (4) On the other segment, logs were carried in the eastbound direction only during the study period.